[R] Sorting based a custom sorting function

Martin Møller Skarbiniks Pedersen tr@xp|@yer @end|ng |rom gm@||@com
Thu Dec 14 09:00:12 CET 2023


  I need to sort a data.frame based on a custom sorting function.
  It is easy in many languages but I can't find a way to do it in R.

  In many cases I could just use an ordered factor but my data.frame
contains poker hands and
I need to rank these hands. I already got a function that compares two hands.

Here is a MRE (Minimal, Reproducible Example):

df <- data.frame(person = c("Alice", "Bob", "Charlie"), value =
c("Medium", "Small", "Large"))

# 0 means equal, -1 means left before right, 1 means right before left
custom_sort <- function(left, right) {
  if (left == right) return(0)
  if (left == "Small") return(-1)
  if (left == "Medium" & right == "Large") return(-1)

#  sort df according to custom_soft
# expect output is a data.frame:
#     name   size
# 1     Bob Medium
# 2   Alice  Small
# 3 Charlie  Large

In this simple case I can just use an ordered factor but what about
the poker hands situation?


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